Power converters are used to transfer electrical energy from one circuit to another. For example, energy is transformed from the power grid to a load while converting voltage and current characteristics. Switching power converters are increasingly used to replace linear regulators and transformers because they offer high efficiency, small size and reduced weight.
A resonant converter of the type indicated above has been described by A. Sokolow “100-kW DC-DC Converter Employs Resonant-Filter”, published on the Internet site Power Electronics in December 2010. Such converters are particularly attractive for high power applications, i.e., for a power in the order of magnitude of 10-100 kW.
Known resonant converters may be operated at a fixed source voltage and under stable load conditions, so that it is possible to configure the converter such that a Zero Voltage Switching mode of operation (ZVS) is reached or at least approximated. This means that each switch should be switched to the ON state at a timing when the voltage drop across this switch crosses zero or at least reaches a minimum (valley switching), so that switching losses are reduced to minimum.